1. Field of the Invention
The present invention relates to a method and a system for correcting an engine torque based on a vehicle load, and more particularly to a method and a system for correcting an engine torque based on a vehicle load that can secure drivability to some degree under various vehicle loads when acceleration or deceleration.
2. Description of Related Art
Generally, an engine torque in a vehicle is controlled by controlling a fuel injection amount and an intake air amount depending on intention of a driver and the controlled engine torque is delivered to a driving wheel through a transmission. Therefore, the vehicle can be accelerated or decelerated according to acceleration intention or deceleration intention of the driver.
An accelerator pedal and a brake pedal for perceiving the acceleration intention or the deceleration intention of the driver are provided in the vehicle. If the driver has the acceleration intention, he or she pushes the accelerator pedal deeply. If the driver has the deceleration intention, he or she takes his or her foot off the accelerator pedal and pushes the brake pedal.
If the acceleration intention or the deceleration intention of the driver is transmitted to a control portion of the vehicle as described above (i.e., the accelerator pedal is pushed or the brake pedal is pushed), the control portion calculates a target engine torque according to the acceleration intention or deceleration intention of the driver. At this time, the control portion uses a predetermined torque map. After that, the control portion controls an engine according to the calculated target engine torque. That is, the control portion controls a fuel injection amount, an intake air amount, a fuel injection timing, and so on.
Meanwhile, if the engine torque is increased or reduced to the calculated target engine torque quickly, impact may occur. Therefore, drivability may be deteriorated. Therefore, the control portion uses a torque filter in order to increase or reduce the engine torque to the target engine torque slowly.
A conventional torque filter, however, is used assuming that a vehicle load is constant. Therefore, it is hard to secure favorable drivability under various vehicle loads when acceleration or deceleration. For example, if the conventional torque filter is used assuming the vehicle load is constant when a fully loaded truck or an overloaded bus is accelerated or decelerated, shock or jerk may occur.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.